Effect of alumina addition on the microstructure of plasma sprayed YSZ

A plasma spray process for fabricating yttria-stabilized zirconia (YSZ) layers for SOFC was investigated. YSZ powders (CERAC, USA) <44 μm in diameter have been used to prepare plasma-sprayed ceramic films on the stainless steel sheets employing non-equilibrium plasma spray technology at atmospheric pressure. The effect of alumina addition from 1 to 5 wt.% on the properties of plasma sprayed YSZ films was investigated. Plasma sprayed zirconium oxide films have been characterized using scanning electron microscope (SEM) and X-ray diffractometer (XRD) for study of microstructure and phase analysis. The phase content and crystallite size of the films have been evaluated. The dependence of deposit characteristics on the concentration of additive was investigated and revealed that proper amount of alumina addition can improve the properties of plasma sprayed YSZ films. It was demonstrated how the started powder composition affects the density of the obtained films.